though it is also dependant on the impedance of the speakers,
Some of my subs run at 4ohm and my sub amp's output at 4 ohm is 1500watts per channel, 2 subs = 3kw
though my tops run at 8ohm and my top amp's output at 8ohm is 500 watts per channel. 2 tops = 1kw
HK stuff sounds nice but IMO unnatural.
Active alternatives could be the forty and fifty line systems or the fohhn xperience slightly pricier though.
Live Sound and Studio Engineer